ALTON — “On the 16th of December, 1811, about two o’clock, A.M., we were visited by a violent shock of an earthquake, accompanied by a very awful noise resembling loud but distant thunder, but more hoarse and vibrating, which was followed in a few minutes by the complete saturation of the atmosphere, with sulphurous vapor, causing total darkness.
“The screams of the affrighted inhabitants running to and fro, not knowing where to go, or what to do — the cries of the fowls and beasts of every species — the cracking of trees falling, and the roaring of the Mississippi — the current of which was retrograde for a few minutes, owing as is supposed, to an irruption in its bed — formed a scene truly horrible.”
Eliza Bryan’s firsthand account of the 7.5-magnitude earthquake that occurred in New Madrid, Mo., on Dec. 16, 1811, appeared in the 1849 book entitled “Lorenzo Dow’s Journal.” She goes on to chronicle the scenes that followed the early-morning quake — the Mississippi River “gathering up like a mountain” before crashing down on its banks, the earth being torn to pieces, the fear of their houses falling down around them leading them to live in “little light camps made of boards” for more than a year after the event.
Other eyewitness accounts of that earthquake and the two that followed in the subsequent months, both nearly as powerful as the first — by magnitude, the three earthquakes rank among the top 20 in U.S. history — appear on the U.S. Geological Survey website. Like Bryan, they describe similar horrors. George Heinrich Crist, who was living in Nelson County, Ky., said it “was the worst thing I have ever witnessed.”
Since the last of the major earthquakes on Feb. 7, 1812, the New Madrid Seismic Zone has remained relatively quiet. Smaller earthquakes happen along the fault line, which stretches from the southern tip of Illinois southwest through Missouri and into parts of Tennessee and Arkansas, all the time — a 3.4-magnitude earthquake in Tiptonville, Tenn., was reported on Sept. 9 — but nothing has approached the catastrophic levels of those 1811 and 1812 quakes.
A ticking clock?
According to the Missouri Department of Natural Resources, that may be about to change. The Missouri DNR website posits the seismic zone “appears to be about 30 years overdue” for a major event, noting the last earthquake of 6.3-magnitude or higher was in Charleston, Mo., on Oct. 31, 1895.
Despite the relatively dormant period, Robert Williams, coordinator for the USGS Earthquake Hazards Program in Central and Eastern United States, said that doesn’t guarantee something is going to give any time soon.
“We don’t know enough about the New Madrid Seismic Zone to say whether or not it’s overdue,” Williams said. “We still have the same concern for a large, damaging earthquake in New Madrid, like the 1811-1812 events.
“It comes from the repeated sequences like that that go back in prehistoric time, that geologists have found evidence for similar-sized earthquakes there. So, we’re continuing to support agencies like FEMA and state emergency management agencies to discuss preparedness for earthquakes in New Madrid, as well as other regions closer to Illinois.”
In 2006, the USGS convened a workshop of experts to evaluate the latest findings on the region. Although little seismic activity had been recorded by global positioning system instruments, the panel could not find a reason to lower the assessment of earthquake hazard in the New Madrid region.
Williams said the USGS monitors earthquakes in the region 24 hours a day, seven days a week, including working in conjunction with researchers at the University of Memphis and Saint Louis University.
They also conduct internal research on earthquake hazards in the region. A recently published paper by USGS geophysicist Will Levandowski suggested characteristics about the density of rocks under the earth’s surface that may be unique to New Madrid could help explain why repeated big earthquakes occur in the region.
And while the New Madrid zone receives the most attention, Williams said it’s not the only concern for Southern Illinois residents.
“It’s not just the New Madrid Seismic Zone that we’re worried about,” Williams said. “We do think the strongest ground motions for the St. Louis region from earthquakes are most like to come from New Madrid down to the south, but there’s also the Wabash Valley Seismic Zone, and that lies directly to the east along the Illinois-Indiana border.
“That region has a history and a prehistoric record of earthquakes, possibly up to magnitude 7. And there has been damage in St. Louis, very minor damage, from magnitude 5 earthquakes in my lifetime … from earthquakes to the south and east of St. Louis.”
Hitting close to home
What an earthquake could mean to the Riverbend depends on a number of factors.
Michael Grossman, graduate program director for Southern Illinois University Edwardsville’s Department of Geography, said even slight variations in magnitude could result in vastly different experiences locally.
“We’ve felt small shakes around here, and occasionally things fall down, but it really depends on the size,” Grossman said. “There’s a great difference between the sizes. The difference between a 5 and a 6 (on the magnitude scale) is big, and the difference between a 6 and a 7 is big.
“Now, what would happen around here? It really depends on how big an earthquake you get. Certainly, something in the 5-6 range, people would feel it, it would knock things off shelves, maybe some old chimneys would be damaged, but you probably wouldn’t get any major damage.”
Likewise, Grossman said duration would have an effect on an earthquake’s impact — “15 seconds is all it takes to wreck a place,” he said — and he said places like Alton, with many homes and businesses a stone’s throw from the banks of the Mississippi River, could be more greatly affected than some of its inland neighbors.
“Closer to the river, on any kind of soft sediments like sand, silts and clays, there would be more movement — you’d get liquefaction, you’d get possibly damage to roads and bridges,” Grossman said. “So, anything that’s near water is going to have a little bit more damage than stuff that’s up on the solid rock.”
Grossman, who has lived and studied in Japan — prone to earthquakes and other natural disasters because of its location along the Pacific Ring of Fire — said he tells his students it’s probably a question of when, not if, another major event takes place in the region.
“It’s likely to happen in our lifetime,” Grossman said. “Something. How big, no one knows.”
If and when an earthquake hits the area, the key, according to Illinois Emergency Management Agency’s Patti Thompson, is to be prepared.
September is National Preparedness Month, a month to remind citizens “that we all must take action to prepare, now and throughout the year, for the types of emergencies that could affect us where we live, work, and also where we visit,” according to the Department of Homeland Security’s website. Like last year, this year’s theme is “Don’t Wait, Communicate. Make Your Emergency Plan Today.”
Thompson, a spokeswoman for IEMA, said the key to staying safe during and after an earthquake actually starts well before the ground begins to shake.
“One of the most important things that they can do is learn in advance what steps that they can take to try to protect themselves and to mitigate some of the damage,” Thompson said.
That includes anchoring heavy objects like bookshelves to the wall. Having a minimum three-day supply of water and non-perishable food, as well as knowing the locations of radios and flashlights, is also important preparation for a major event.
Thompson cautioned that while an earthquake is a preeminent fear for this part of the country, it’s not the only reason for people to ensure they’ve taken the necessary steps for preparedness.
“We have a lot of things that can happen here in Illinois — we can see tornadoes or ice storms or flooding, things that could cause you to need to fend for yourself for up to three days if emergency workers were unable to get to you,” Thompson said. “Certainly, the major earthquake scenario is one of those events that really could put you on your own, when you think about the type of damage that a major earthquake could cause — we’d have road damage, we’d have bridge damage, we’d have widespread utility outages. So, with so many issues created, not only could it be hard for first-responders to get to you, but it could also be that they’re so overwhelmed with the numbers of people that they have to respond to.”
Thompson cited the preparedness motto “Drop, Cover and Hold On” as the thing to remember during an earthquake — drop to the ground, take cover by getting under a sturdy desk or table, and hold onto it until the shaking stops. Grossman echoed that motto.
“The main thing is to protect yourself from falling objects, and then shut off anything that has the potential to start a fire,” Grossman said. “After that, if it looks like there’s any structural damage, you may then want to go outside, but stay away from power lines.”
The Great ShakeOut: A national earthquake exercise
Practice makes perfect, and that holds true for earthquake preparedness as well.
The Southern California Earthquake Center instituted the Great ShakeOut earthquake drill to educate individuals on what to do in the event of an earthquake. The drill has grown into a worldwide event, and this year’s exercise will take place at 10:20 a.m. Thursday, Oct. 20.
“We’re hoping that hundreds of thousands of people across the state will be participating in that drop, cover and hold on exercise,” Thompson said. “Not only just because of the earthquake risk that exists in Illinois, but also because people travel throughout the country and around the world, and we’ve seen many major earthquakes happen around the world in the last few years.”
More than 400,000 Illinois residents are registered to participate in this year’s event, a fraction of the more than 21 million individuals expected to participate across the country. Local participants include East Alton-Wood River High School, Maryville Elementary School in the Granite City School District, Jerseyville East and West elementaries and Jersey Community High School, Roxana’s Central Intermediate School, Hartford Elementary, St. Francis/Holy Ghost School in Jerseyville, Ss. Peter and Paul School in Alton and Zion Lutheran School in Bethalto.